This is a reasonable and common concern, and one I shared until I looked into it in fine detail. Turns out it's far easier to estimate the value of land that things sit on than the entire property value, and most of the country actually operates on continually updated estimates of total property value rather than just land.

There's several anchoring sales nearby, you can regress out from all sales, etc. etc. And it's smoothly varying for nearby parcels, with very little change!

A much better explanation than what I can write can be found in the "Estimating" section here https://landeconomics.org/reports/california-billionaire-wea...

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sokoloff 4 hours ago | parent [-]

I will read that link later tonight (thanks!), but this still seems like a system where a particular property owner could be “targeted” (politically or economically) and suffer without reasonable legal recourse.

	▲	epistasis 2 hours ago \| parent [-]
		It's actually much harder to target a particular owner, because it's based only on land area, and the value of land in a general area! Property taxes are much much more susceptible to targeting as individual properties are much more variable and there's far more judgement about individual buildings and the potential value of a building.